Fix deprecation warnings seen with docker-py >= 1.4 when passing arguments to docker_client.start().

GitHubEventHandler now uses the ['repository']['html_url'] key in the webhook payload to populate repository, as the previously used ['url'] and ['clone_url'] keys had a different format between push and pull requests and GitHub and GitHub Enterprise instances.

Fix race condition where log compression could lead to empty log results in reporter api

Error while applying db upgrade is now properly reported in the buildbot upgrade-master command line.

Made Interpolate safe for deepcopy or serialization/deserialization

Optimized UI REST requests for child builds and change page.

Fix DockerLatentWorker use of volume parameter, they now properly manage src:dest syntax.

Fix DockerLatentWorker to properly create properties so that docker parameters can be renderable.

Lock down autobahn version for python 2.6 (note that autobahn and twisted are no longer supporting 2.6, and thus do not receive security fixes anymore).

Worker changes described in below worker section will probably impact a buildbot developer who uses undocumented ‘slave’ API.
Undocumented APIs have been replaced without failover, so any custom code that uses it shall be updated with new undocumented API.